1. Field of the Invention
This invention relates to a vehicle windshield and more particularly to an assembly for adjustably mounting such windshield on the handlebars of mopeds, bicycles, motorcycles, snowmobiles or the like.
2. Description of the Prior Art
With the advent of motorcycles and mopeds capable of increased speeds and with stricter safety standards requiring safer windshields, there has been a corresponding demand for economical windshield assemblies. However, problems have been encountered in adequately supporting the windshields with the stability and safety required and expected.
For example, a windshield is subjected not only to bending moments and other forces resulting from its deflection by the air but also intermittent forces applied to the windshield and its mounting assembly as the vehicle encounters bumps, depressions and irregularities in the roadway surface. When a vehicle passes over an irregular road surface, the stresses generated by the impact are generally transferred from the wheels, through the vehicle suspension wherein the stresses are partially absorbed and dampened, and subsequently distributed to various parts of the vehicle such as the windshield. Small motorcycles and mopeds are usually provided with a comparatively smaller and less complex suspension assembly than relatively larger motorcycles and, accordingly, a greater degree of the impact resulting from roadway irregularities may be transferred to the windshield through the handlebars and windshield mounting members extending therebetween.
Additionally, a particular windshield element is subjected not only to various externally applied forces but also stress concentrations resulting from material imperfections; discontinuities such as holes or notches; irregular deflections of the windshield such as would occur where the windshield is unevenly constrained by a windshield mounting member or the like; and other defects. For example, windshields commonly employed on mopeds and small motorcycles often include a pair of vertically spaced mounting holes extending therethrough for receiving fasteners for attaching a windshield to vertical supports which are connected to handlebars. Although the fasteners usually include rubber sleeves or cushions to reduce the impact force transmitted to the area adjacent the windshield holes, a failure, such as by fracture, of the region of the windshield adjacent a connection hole may result from repeated loads with possible dangerous consequences to a vehicle operator. The propagation of a crack about a windshield hole is also likely in view of the relatively high stress concentrations which occur adjacent holes, notches and other physical irregularities when a load or force is applied to the windshield. Failure of a windshield element may result not only from material defects but failure may also occur as a result of the means or manner by which the windshield is constrained. For example, a relatively thin windshield element rigidly constrained at one or more points may experience severe localized stresses adjacent the mounting point where the deflecting windshield is improperly and/or too rigidly constrained. Therefore, windshields for mopeds and relatively small motorcycles may experience performance problems resulting not only from inherent material and design defects but also resulting from the manner of their installation.
Accordingly, it would be preferable to employ an economical, lightweight mounting member for the handlebars of a relatively small motorcycle or moped which is designed not only to absorb vibrations due to irregular roadway surfaces but also adequately supports the windshield without unduly stressing the regions adjacent one or more mounting holes. Furthermore, reductions in costs of the mounting assembly are important so that the windshield and mounting assembly may be competitive and affordable to the average user of such mopeds and/or bikes.
Windshield mounting assemblies which commonly include handlebar clamping portions and windshield mounting members respectively connected to the clamping portions and a windshield are generally disclosed in U.S. Pat. No. Re. 23,039, 1,532,008, 2,675,266, 3,801,152 and 3,904,238. Of somewhat related interest are U.S. Pat No. 1,498,848 and 1,571,563 which generally disclose a windshield element disposed between two clamping members.
The windshield mounting member constructed according to the present invention is designed to overcome various problems, such as the probable failure of the windshield or its mounting member, which may be encountered with some of the prior art, and to provide a better distribution of forces between the windshield and its mounting members. For example, a relatively large amount of the applied loads transferred between a windshield element and the windshield mounting member constructed according to the present invention may be transmitted as frictional resistance between the surface portions of the mounting member and abutting surface portions of the windshield element thus avoiding many performance problems such as would normally occur with a bearing type connection wherein a windshield is supported by fastening means which extends through a windshield mounting hole and generally engages the edges thereof.